Wrench.



PATENTED JULY 10, 1906.

J. MEROKENS.

WRENCH. APPLIUATION FILED DBO. 5. 1904. RENEWED DEC. 8. 190a.

-Unrirnn STATES PATENT OFFICE.

JOHN MERCKENS, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE EDMONDS- METZEL MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS.

WRENCH.

Specification of Letters Patent.

Patented July 10, 1906.

Application filed December 5, 1904. Renewed December 8, 1905. Serial No. 290,962.

strength and efliciency, and to provide an improved arrangement of parts whereby the gripping parts of tempered steel may be efectively reinforced byless brittle and tougher material. I accomplish these objects by the device shown in the accompanying drawings, in which Figure 1 is a plan view of a wrench and thread-retracting device constructed according to my invention. Fig. 2 is a longitudinal section of the same on the line 2 2 of Fig. 1. Fig. 3 is a plan view of one of the toothed sections of the same, showing the thread-cutting dies in position therein. Fig. 4 1s a plan view of the middle reinforcing-plate.

The device shown in the drawings consists of a handle 5, having a plurality of thread-retracting die-sockets of difierent sizes in its middle part and having at each end a pair of wrench-jaws 6, which are disposed at an angle to each other and provided with grippingteeth 7 at one side, so as to be suitable for gripping either pipes or nuts.

The handle and jaws of the wrench are of laminated structure and preferably consist of alternate plates of tool-steel and of annealed steel or other tough malleable metal. The tool-steel plates 8 are provided with projecting teeth 7 at one side of each wrench-head and are tempered to give the teeth the desired degree of hardness. The tool-steel plates 8 are separated by a plate 9 of annealed steel and bound together by the exterior plates 10 and 11, which are also of annealed steel. All of these plates are secured together by means of a plurality of screws 12, which have threaded engagement with the plate 11 and which are provided with heads countersunk into the plate 10.

The plates 10 and 11 are provided at their middle part with an oval aperture 13, while the intermediate plates are provided with rectangular apertures 14 and with tongues 15, extending into said apertures. The apertures 14 are of exactly the same shape and form within the body of the handle 5 a cavity for retainnig a pair of die-plates 16, which are separated by the tongues 15 to form a slot 17 for cuttings. The die-plates 16 are provided with thread-cutting sockets 18, as shown. The die-plates 16 are retained within the handle by the cover-plates 10 and 11. The thread cutting device which is herein shownis not claimed herein, but is more fully described and claimed in my copending application, filed April 17, 1905, Serial No. 255,978. The edges 19 of the soft plates extend beyond the bases or roots 20 of the teeth. The support thus given 'the teeth tends to prevent the same from breaking within the protecting edges 19, and in case the teeth are broken flush with the ed es 19 then said edges may be filed back, rendering efitective a new gripping-surface.

It will be seen that the plates which form the handle-jaws and teeth of the device are of such form that they may be readily stamped from sheet metal. The toothed plates may then be tempered to the exact degree of hardness desired. Where similar devices are made with wrench-jaws of one piece and hardened to the desired degree, the tempering process renders the material brittle and easily broken. In a Wrench constructed according to my invention this brittleness of the tempered parts is offset to a large extent by being reinforced by the annealed supporting structure. In the older forms of devices of this class it is customary to make the wrench-jaws and thread-cutting dies of a single piece of material, and the breaking of any part, such as a single tooth in one of the jaws, or injury to the threads of one of the die-sockets, reatly impairs the utility of the entire tool, while in a device constructed according to my invention any broken part can be readily replaced at small expense, thus prolonging the life and maintaining the highest efliciency of the tool indefinitely. Another important savin in the expense of constructing the wrench-heads according to my invention lies in the fact that the teeth 7 are formed complete during the sin le operation of stamping the plates 8, whi e in the prior wrenches of this type it has been necessary to form the blank without teeth and then mill the teeth as a later step in the process of manufacture. When the teeth are milled, acuteness of angle of the gripping-face of the teeth is limited by the angle of the opening between the jaws. This is illustrated in Fig. 3, where the dotted line 21 represents the center line of a rotary milling-tool which will cut teeth upon one jaw and just clear the face 22 of the opposite jaw. The most acute out which such a milling-tool can make in the toothed jaw is shown by the line 23, which is at right angles to the line 21. When the teeth are stamped from a plate, as hereinbefore described, there is no such limitation.

The operation of the device shown is wellknown and will be fully understood from the foregoing description.

What I claim as my invention, and desire to secure by LettersPatent, is

1. A wrench having a pair of jaws with opposed grip ing-surfaces, and comprising a lurality o superimposed plates of similar orm, lying in planes extending through both jaws and being secured together, one of said plates being of tempered steel and having teeth projecting from one of said gripping surfaces, each of said plates being of uniform thickness throughout and being adapted to be stamped from'sheet metal, substantially as described. i

2. A wrench having a pair of jaws with op posed gripping-surfaces, and comprising a plurality of superimposed plates of similar ormlying in planes extending through both jaws and being detachably secured together,

one of said plates being of tempered steel and having teeth projecting from one of said grippingssurfaces, substantially as described.

3. A wrench having a pair of jaws with 0pposed gripping-surfaces, and comprising a plurality of parallel plates of tempered steel, reinforced by alternate plates of untempered metal, and said tempered plates being provided with teeth projecting from one of said gripping surfaces, substantially as described.

4. As an article of manufacture, a tool comprising a flat plate of hard metal having teeth on one edge, and a pair of plates of softer metal of substantially the same outer con tour as said hard plate, said softer plates be ing secured respectively to opposite faces of said hard plate and registering therewith at their edges and adapted to support and reinforce said hard plate, substantially as described.

5. As an article of manufacture, a tool comprising a plurality of flat plates of soft metal, and a plurality of plates of relatively harder metal interposed alternately between said softer plates, all-of said plates having substantially the same outer contour, being rigidly secured together, the harder plates havin g teeth along one edge projecting beyond the corresponding edges of the softer plates, substantially as described.

Signed at Chicago this 18th day of November, 1904.

JOHN MERCKENS. Witnesses:

WM. R. RUMMLER, A. E. METZEL. 

